Process and apparatus for the production of artificial filaments or threads



July 14, 193 H. DREYFUS ET AL $514,463

PROCESS AND APPARATUS FOR THE PRODUCTION OF ARTIFICIAL FILAMENTS 0R THREADS Filed Nov. 29. 1927 5 Shets-Sheet l FIGB- July 14, 1931. H. DREYFUS ET AL 1,814,458

PROCESS AND APPARATUS FOR THE PRODUCTION OF ARTIFICIAL FILAMENTS 0R THREADS Filed Nov; 29. 1927 5 Sheets-Sheet 2 '6 mugmm 55 2.

/ nf-Tm H. DREYFUS ET AL PROCESS AND APPARATUS FOR THE PRODUU'JJLON 0F ARTIFICIAL FILAMENTS 0R THREADS Filed Nov. 29; 1927 5 Sheets-Sheet 3 July 14 1931.

y 1 1931- H. DREYFUS ET AL ,468

PROCESS AND- APPARATUS FOR THE PRODUCTION OF ARTIFICIAL FILAMENTS OR THREADS Filed NOV. 29. 1927 5 Sheets-Sheet 4 FIQG-8 III II Ill/Ill,

' July 14, 1931.

I2. DREYFUS ET AL 1,814,463 PROCESS AN APPARATUS FOR THE PRODUCTION OF ARTIFICIAL FILAMENTS OR THREADS Filed Nov. 29. 1927 5 Sheets-Sheet 5 INVENTORS HENRY DREYFUS EDWARD -KINSELLA JOSHUA BOWER WILLIAM I. W3

*ATTOR J S Patented July 14, 1931 uNirsn stares PATENT OFF ICE HENRY DEEYF'US, 0E LONDGN, EDWARD KINSELLA, JOSHUA BOWER AND WILLIAM IVAN TAYLOR, 0F SPQNDON, NEAR DERBY, ENG-LAND, ASSIG-NORS TO CELANESE CORPORATION OF AMERICA, A CORPORATION OF DELA'W'ABE v PROCESS AND APPARATUS FOR THE rnonncrron or ARTIFICIAL FILAMENTS on rnnnnns Application filed November 29, 1927, Serial No. 236,448, and in Great Britain. May 23, 1927.

This invention relates to processes and apparatus for the manufacture of artificial silk or like filaments or threads from solutions of cellulose acetate or other derivatives of cellulose, such as other esters of cellulose or cellulose ethers, by extruding or spinning the solutions into closed or substantially closed chambers, such as the cells or compartments either in the air or gas duct leading to the spinning chambers or at the bottom of the spinning chambers or alternatively or in addition by heating devices disposed in the spinning chambers at any convenient height or heights with respect to the spinning noz-- zle or nozzles, for example by heating devices disposed at the front and/ or back of the spinning chambers. With such heating devices the whole casing or casings oi the spinning chambers become heated and to some extent the spinning solutions are also heated prior to extrusion or spinning, by conduction through the pipe or pipes conveying the solutions to the nozzles. This is especially the case if spinning chambers are employed which have thermally insulated or lagged walls and/ or tops, but particularly thermally insulated tops, and in consequence of such heating of the spinning solutions the total heat, whether supplied by steam or by other heating means, is reduced to a minimum. For example the main distributor pipe for the spinning solution and its branch pipes to the nozzles may be carried within the casing of the spinning cells or chambers so that they become heated by the Warm air or other evaporative medium- Flat low roots to the spinning rooms aid the general mamtenance of heated conditions. However in addition or alternatively the spinning solutions may be heated by means of heating devices disposed in or around the nozzles themselves or the pipes leading thereto or prior to entry into the pipes. Furthermore it may be mentioned that, if the spinning solutions are heated either prior to or whilst passing through the filter presses, not only is the spinning solution supplied warm or hot to the nozzles but the capacity of the filter presses is increased. In such prior processes, some at least of the evaporative capacity of the air or other medium is lost.

We have now found that the full evaporative capacity of the air or other medium, whether heated or not, may be utilized by employing collector devices adapted to limit the passage for the air or other medium so that practically the whole is constrained to pass through the immediate vicinity of the nozzle or nozzles. Preferably the collector devices are such as to cause practically all the evaporative medium to impinge upon the nozzie face or to pass as close as possible round it. Any convenient form of apparatus may be used toefiect this purpose.

We have further found that the use of such collector devices enables a much stricter control to be exercised over the cross-section of the filaments obtained and fiat or semi-flat or substantially rounded filaments may be obtained at will by suitably adjusting the conditions. Thus practically 100% of the flat or of therounded or of anyintermediate form may be obtained. In addition the solvent vapours drawn oil from the spinning cells or chambers are not diluted with the evaporative medium to an unnecessary extent and in consequence the recovery of the solvent vapours is rendered correspondingly less expensive.

The improved apparatus may comprise a spinning chamber or cell, a spinning nozzle or nozzles therein, and a. collector device, such for example as a perforated plate (a plate cut with a hole or holes), a hood, funnel, cylinder, shield or like member, adapted to limit the passage for the air or other evaporative medium so that practically the whole passes through the immediate vicinity of the spin ning orifice or orifices and preferably adapted to cause practically the whole of the evaporative medium to impinge upon the nozzle face or faces or to pass as close as possible round the same. Any number of such units may be used together or be combined in one metier casing.

The present invention is more particularly adapted for use in downward spinning and will be hereinafter described with reference thereto, but it is to be understood that it is not limited to this method of dry spinning.

The apparatus of the present invention may in its simplest form consist of a spinning cell or chamber tapering towards the spinning nozzle or nozzles, or alternatively a device such for instance as perforated plate (with one, two or more holes according tothe number of nozzles) or an inverted funnel-shaped member or a hood or the like may be provided, such device extending across the entire cross section of the cell or chamber (whether this is of uniform cross-section or of tapered or other form), with the exception of an area above, around, or below the spinning nozzle or nozzles, the device being supported in any convenient manner, for example, it may be directly attached to the wall of the cell or chamber, or be carried by supports thereon or carried by means of a spider member engaging the pipe conveying the spinning solut1on to the nozzle or nozzles.

In any such case the solvent-laden evaporative medium may be withdrawn in any convenient manner, but preferably the actual draw-01f is arranged centrally above the nozzle or nozzles. For example, the draw-off arrangement may comprise one or more downwardly extending tubular members terminating (with a flared end or not) at a point above the nozzle or nozzles, one such member being preferably arranged above each nozzle.

Where aplurality of draw-off members is employed with one cell or chamber they may,

if desired, be joined either inside or outside the chamber or cell. In some cases a special type of draw-off, itself adapted to assist in causing the air or other evaporative medium to pass as close as possible to, or through the immediate vicinity of, the spinning orifice or orifices, may be used with advantage. Thus for example a draw-0E may be provided con sisting of a pipe or pipes of annular or other suitable form connected to the exhaust system and disposed above (for example some distance vertically above) or around, i. e. in about the same plane as, the spinning nozzle or nozzles, the said pipe or pipes having a number of perforations or slits or a continuous slit to act as outlet for the evaporative medium. Such an arrangement is especially useful when nozzles of the perforated ring type are employed but it may also be used with the perforated disc type or other type of nozzle.

Another type of collector device according to the present invention comprises a hood, inverted funnel, bell-shaped member, cylinder (which may be flared or not at its lower edge), or the like attached to and forming a substantially air-tight oint with the pipe used to convey the spinning solution to the nozzle or nozzles, such device being provided with a nipple or a series of nipples or other exit arrangement leading to the exhaust sys tem for the evaporative medium. With such a. collector device it will be at once obvious that it is by no means necessary for the device to extend across the entire cross-section of tee spinning chamber, for, since the only outlet for the gaseous medium is through the collector device, all the air or other evaporative medium must pass through th immediate vicinity of the spinning orifice or orifices. Such collector devices may, if desired, be used in conjunction with the types of collector device previously described. For example very good results are obtainable by employing a perforated plate disposed below a hood, inverted funnel, bell-shaped member or the like directly connected as described above with the exhaust system.

lVhatever type of collector device is employ-ed according to the present invention, a single collector device may be used for each chamber or cell of the spinning plant, whether the chamber or cell contains one, two or other small number of nozzles, or alternatively, and this arragnement is to be preferred, each nozzle may be provided with its own individual collector device.

The height of the collector devices with respect to the spinning nozzles will determine to some extent the exact proportion of the evaporative medium which impinges on the nozzle and it will be obvious that some of the devices described above are adapted to be used above or around the nozzles, others below or around the nozzles, while some may be used above, below or around the nozzles.

We prefer to mount the collector devices of the present invention, and particularly such as are attached to the pipe or pipes carrying the spinning solution to the nozzle 01' nozzles, so that they are slidingly or otherwise adjustable and thus permit of ready access to the nozzles. In such a case the collector device may be a sliding fit on the pipe and a spring clip may be provided to retain it in position, or in other cases the collector device may be supported by flexible wires carried over pulleys at the top of the spinning chambers. Further, collector devices which are adjustably mounted and are directly connected with the exhaust system may be so connected by means of a flexible line, such as a rubber or flexible metal conduit, in order to permit of easy adjustment.

The devices of the present invention are preferably used in conjunction with outlet pipes for the solvent-laden evaporative medium provided with valves, constrictions or other devices for controlling or regulating more collector devices may be connected to' each pipe carrying a control device.

According to a modification of the process of the present invention, instead of practically the whole of the air or other evaporative medium being constrained to pass through the immediate vicinity of the spinning orifice or orifices, a definite proportion only, which may be adjusted at will, is so constrained.

The improved apparatus described above and preferably that comprising collector dev...taining still or substantially still air or other vices connected directly with the exhaust system may be used for carrying out this modification of the invention. Instead however of the space around and above the collector congas, as is the case where a collector device directly connected with the exhaust system is used to carry away the whole of the air or other gas, a draw-off in this part of the cell .or chamber is provided and preferably a draw-off controlled as referred to above. Thus by suitably adjusting either the control device associated with the draw-off from the collector device or the control device asso- ..ciated with the draw-oft from the space around and above the collector device or by adjusting both, a definite proportion of the air or other evaporative medium passing through the cell may be constrained to pass through the immediate vicinity of the spinning orifice or orifices. The air or other gas from the two draw-off systems may be mixed together and the solvent recovered, but preferably they are subjected separately to proc- .esses for the recovery of the solvent contained around and above the collector devices. 'ternatlvely however 13118311 or other gas from therein, since the air or other gas which has passed through the collector devices will contain a much greater proportion of solvent vapour than that drawn off from the spaces and in addition it allows of controlling the i cross-section of the filaments as explained above.

The collector devices either in the main invention or in the modification thereof may be made of any suitable material, preferably a conductive metal, and may, if desired, be provided with heating means whereby the evaporative power of the air or other gas used in the spinning cells may be increased at the moment it enters the vicinity of the spinning orifice or orifices. The heating means may be electrical or may comprise pipes, through which passes steam, hot water or other heating fluid, the pipes being provided, if desired, with radiating fins.

The accompanying drawings illustrate some examples of apparatus constructed in accordance with the present invention, but it will be understoodthat the invention is in no way limited thereto. p

Figure 1 is a front view of part of the up per portion of a spinning cell containing two spinning nozzles, the cell and collector devices being shown in vertical section.

Figure 2 is a plan of another collector device, and Figure 3 is a side view of part of the upper portion of a spinning cell fitted with the collector device of Figure 2, the cell and collector device being shown in vertical section.

Figures 4, 5 and 6 illustrate further exam ples of collector devices, these devices being in each case connected directly with the exhaust system for the evaporative medium.

Figure 7 is a front view of part of the upper portion of a spinning cell with collector device provided with heating means, the cell and collector device being shown in vertical section.

Figure 8 is a side view of the upper portion of a spinning cell fitted with a collector device and special draw-off, the cell, collector device and draw-ofi belng shown 1n vertical section. Figure 9 1s a sectional view of a splnning cell provided with collector and draw-off devices as shown in Figure 8, the draw-01f device being in controlled communication with the exhaust system for the cell.

Referring to Figure 1, two rectangular funnel-shaped collector devices 1, are supported in a spinning cell 2, for example by means of a flexible wire (not shown) passing over a pulley at the top of the cell and then moreover their position may be adjusted as required.

In Figures 2 and'3, a plate 4 of thin metal perforated with two circular holes 5, 6 is supported on brackets 7 in a cell 8 so that the holes are centrally beneath the nozzles 9. The air or other evaporative medium is thus deflected by passage through the holes on to the nozzle faces. For convenience of access to the nozzles the plate 4 may be divided into two separate halves along a line passing through the centres of the holes 5, 6, access being obtained by means of a door 10 at, the back of the cell.

Figure 4 shows a metal funnel-shaped collector device 11 terminating in a cylindrical portion 12 which is a sliding fit on the pipe 13 leading to the spinning nozzle 14, a side tube 15 and fiexible pipe 16 being provided for drawing off the evaporative medium. A spring clip 17 serves to hold the collector in the desired position. The collector may be raised to allow of access to the nozzle.

The collector device shown in Figure 5 consists of two cylindrical members 18, 19, the upper member 18 being fixed to the pipe 20 leading to the spinning nozzle 21 and being provided with an outlet 22 for the evaporative medium. The upper member 18 carries a leather washer 23 to form an air-tight joint with the lower member 19 which is slotted to receive a screw 24 serving to clamp it in any desired position. The air or other evaporative medium passes directly on to the nozzle face through the opening 25 in the bottom of the member 19, or if desired a plate perforated with a hole of any required dimensions may be placed on the annular flange 26 of the member 19. The plate 27 carried between the member 18 and the pipe 20 and provided with a ring of perforations 28 further serves to localize the flow of the evaporative medium to the immediate vicinity of the nozzle. By loosening the screw 24 and raising the member 19 to the position shown in dotted lines access is gained to the nozzle.

Figure 6 illustrates a method of connecting two collector devices surrounding two nozzles 29 in one cell by means of flexible pipes 30 to a single exhaust pipe 31 for the evaporative medium. As shown the collector devices comprise funnel shaped portions 32 surmounted by spherical portions 33 from which the draw-off pipes 34 are taken and which are terminated by cylindrical portions 35 constituting a sliding fit on the pipes 36 leading to the nozzles.

Figure 7 illustrates a spinning unit with a collector device and heating means. The collector device comprises a rectangular funnelshaped member 37 supported by the cell walls 38 and surmounted by a box-shaped member 39 carrying internal heating pipes 40 through which steam, hot water or other heating fluid is passed The member 39 terwees minates in a cylindrical neck 41 which forms an air-tight joint with the hollow member 42, the latter being provided with an outlet pipe 43 for the air or other evaporative me dium and with a reduced neck 44 clipped to and forming an air-tight joint with the pipe 45 leading to the nozzle. In this and other apparatus according to the present invention, as previously explained, heating pipes, such for instance as those shown at 46, may be provided in the cell below the collector device or devices.

Figure 8 illustrates a spinning cell with collect device and a special form of drawoil for the evaporative medium. The spinning cell 47 having a spinning solution supply pipe 48 leading to a spinning nozzle 49 is fitted with a collector device comprising a cylindrical tube 50' sliding in and forming an air-tight joint with a sheet metal funnel 51. The draw-off comprises an annular pipe perforated on its under side with a series of holes 52a and disposed coaxially with the pipe 48 and slightly above the nozzle 49, connected by a pipe 53 and flexible connection 54 to the exhaust system for the evaporative incdiun'i. The draw-oil is held in position by a. clip 55 or. the pipe 53. Heating pipes 56 serve to heat the evaporative medium.

Referring to Figure 9, the pipe 53 is connected to a pipe 57 that communicates through a valve 58 with a header 59, the valve 58 being controlled by a handle 60 to regulate the flow of evaporative medium. A flow meter 61 is connected to the pipe 57 between the valve 58 and the draw-off device 52. Similar controlled communication is provided between each draw-oif device and the common exhaust header 59.

.lt will be understood that in accordance with the present invention the air or other evaporative medium may either be drawn through the spinning chambers or cells by suction or may be pumped or blown through under an excess pressure, preferably small.

The filaments made by the improved processes and apparatus may be associated, and wound, with or without twisting, outside the spinning cells or chambers as described in U. S. Patent No. 1602125 and with or with out the aid of cap-spinning devices as described in U. S. application S. No. 615682 filed 29 January 1923, or if desired they may be wound, with or without twisting, inside the spinning cells or chambers.

It is understood that any suitable nozzles may be used for the spinning, whether of the perforated disc or other multifilament type or of the singlejet or single filament type.

l v hat we claim and desire to secure by Letters Patent is 1. Process of spinning artificial filaments or threads from solutions of cellulose acetate or other cellulose derivatives comprising spinning the filaments into a current of evaporative medium which for the major part of its flow passes through an area substantially greater than that occupied by the filaments in the neighborhood of the spinning orifices and constricting the passage of the evapora-.

. tive medium in the said neighborhood, so

that substantially the whole of the evaporative medium is constrained to pass through the immediate vicinity of the spinning orifices.

3. A process of spinning artificial silk and like filaments or threads from solutions of cellulose acetates or other cellulose derivatives,

.40 substantially greater than that occupied by the filaments in the neighborhood of the spincomprising spinning the solutions into a current of evaporatlve medlum secluded from the atmosphere and constraining substan-' nin orifices and constrictin 'the assa e of b b D the evaporative medium in the said neighbor hood so that substantially the whole of the evaporative medium is constrained to pass through the, immediate vicinity of the spinning orifices.

. 5. Process of spinning artificial filaments H or threads from solutions of cellulose acetate or other cellulose derivatives comprising spinning the filaments into a current of evaporative medium secluded from the atmosphere which for the major part of its flow passes through an area substantially greater than that occupied by the filaments in the neighborhood of the spinning orifices and constricting the passage of the evaporative medium in the said neighborhood so that substantially the whole of the evaporative medium is constrained to pass through the immediate vicinity of the spinning orifices.

6. A process of spinning artificial silk and like filaments or threads from solutions of cellulose acetates or other cellulose derivatives, comprising spinning the solutions downwards into a current of evaporative me dium and constraining substantially the whole of the evaporative medium by means of collector devices to pass through the immediate vicinity of the spinning orifices, the fiow of the evaporative medium being controlled.

7 A process of spinning artificial silk and like filaments or threads from solutions of cellulose acetates or other cellulose derivatives, comprising spinning the solutions downwards into a current of evaporative medium secluded from the atmosphere, constraining substantially the whole of the evaporative medium by means of collector de vices topass through the immediate vicinity of the spinning orifices, and conveying the solidified filaments continuously out of said secluded evaporative medium.

8. A process of spinning artificial silk and like filaments or threads from solutions of cellulose acetates or other cellulose derivatives, comprising spinning the solutions downwards into a current of evaporative medium secluded from the atmosphere, constraining substantially the whole of the evaporative medium to pass through the im mediate vicinity of the spinning orifices, and conveying the solidified filaments continuously out of said secluded evaporative medium.

9. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle and at least one collector device in said chamber adapted to limit the passage for the evaporative medium so that substantially the whole passes through the immediate vicinityv of the nozzle orifices.

10. Apparatus for'the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle and a draw-off for the evaporative medium disposed centrally thereto, and

at least one collector device in said chamber adapted to limit the passage for the evaporative medium so that substantially the whole passes through the immediate vicinity of the nozzle orifices.

11. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle and at least one collector device in said chamber, connected directly to the exhaust system for the evaporative medium and adapted to limit the passage for the evaporative medium so that substantially the whole passes through the immediate vicinity ofthe nozzle orifices.

12. Apparatus forthe spinning of artificial silk and 1 like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle, at least one collector device in said chamber adapted to limit the passage for the evaporative medium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices and connected directly to the exhaust system for the evaporative medium and a draw-off from the space around and above the collector arrangement.

13. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle, at least one collector device in said chamber adapted to limit the passage for the evaporative medium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices, and means for controlling'the flow of the evaporative medium.

14. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle and a draw-off for the evaporative medium disposed centrally thereto, at least one collector device in said chamber adapted to limit the passage for the ling the flow of the evaporative medium.

15. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinnin chamber, at least one spinning nozzle, at least one collector device in said chamber connected directly with the exhaust system for the evaporative medium and adapted to limit the passage for the evaporative medium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices, and means for controlling the flow of the evaporative medium.

16. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle, and at least one collector device in said chamber provided with heatingmeans and adapted to limit the passage for the evaporative medium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices.

17. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle, and at least one collector device in. said chamber, provided with heating means and connected directly With the exhaust system for the evaporative medium and adapted to limit the passage for the evaporative medium so that substantially the Whole I passes through the immediate vicinity of the nozzle orifices.

18. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least vicinity of the nozzle orifices, and means for controlling the flow of the evaporative medium.

19. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a substantially closed spinning chamber, at least one spinning nozzle, at least one collector device in said chamber provided With heating means and connected directly with the exhaust system for the evaporative medium and adapted to limit the passage for the evaporative medium so that substantially the whole passes through the immediate vicinity of the nozzle orifices, and means for controlling the flow oi the evaporative medium.

20. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a spinning chamber, at least one spinning nozzle and at least one collector device in said chamber adapted to limit the passage for the evaporative medium so that substantially the whole passes through the immediate vicinity of the nozzle orifices.

21. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method, comprising a spinning chamber, at least one spinning nozzle, at least one collector device in said chamber adapted to limit the passage for the evaporative me dium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices, and means for controlling the flow of the evaporative medium.

22. Apparatus for the spinning ofartificial silk and like filaments or threads by the evaporative method, comprising a spinning chamber, at least one spinning nozzle, at least one collector device in said chamber connected directly With the exhaust system for the evaporative medium and adapted to limit the passage for the evaporative medium so that substantially the Whole passes through the immediate vicinity of the nozzle orifices, and

means for controlling the flow of the evapostantially the Whole passes through the immediate Vicinity of the nozzle orifices, and means for controlling the flow of the evaporative medium.

24. Apparatus for the spinning of artificial silk and like filaments or threads by the evaporative method comprising a spinning chamber, a spinning nozzle for said chamber, the cross-sectional area of the said chamber being for the major part of the length of the chamber substantially larger than the area occupied by the nozzle, and a constriction in said chamber in the neighborhood of the nozzle whereby the passage for the evaporative medium is constrained to pass through the immediate Vicinity of the nozzle orifices.

In testimony whereof We have hereunto subscribed our names.

HENRY DREYFUS. EDWARD KINSELLA. JOSHUA BOWER. WILLIAM IVAN TAYLOR. 

